Alloy and process



Patented Mar. 31, 1953 UNITED STATE 5* PATENT QFF'I ALLOYIAND PROCESS ship.

No Drawing-1 Application September 7, 195%, Serial "No. 183,665?

9*Claimst'" (01. 14811-1) The :presentfinvention.has reference to steel like... alloys, and the processes of "making and treating same. The object of. the invention is the productionof novel'alloys having excellent phys-' idaljproperties, in. an economic'almanner, and 5 further objectsinclude the process of producing and. refining and of heat treating th'e said alloys andjarti'clesv composed "of same.-

Thealloyscan be considered as being ;of two" types, namely (a) what I "term semi-alloy"steely? 10k whichis highin carbon and silicon: and'lb') what I term 'alloysteelfffwhich is low imcarbon-and silicon? The said jalloysalso contain "manganese"; andfmolybdenumr These alloys mayalscr corl' tainonlyjtrace quantities of "boron; added-during 71 a the manufacture'of the alloys; Heretofore alloys of this general type-have usuallyhad chromium or nickel orboth'added, and -in'the *prior art-it" was generallynonsidered "that the chromium or" nickel or both were needed to give-"a good--'alloy*-- 20.

ing of. some of the other metals. I find thatthe use of these-metals can-be'wholly"omitted: The said metals; chromium and nickel are notonly highly."expensive, but they produce certain undesirable :properties.inrthelalloys.. That these 25.

We :expensive metals could, .be omitted, .and :the properties of .the. alloys improved, .was not obvious from the prior art. Chromiumis particu-l larly objectionable since it imparts "surface em-. brittlement. to'. the alloys. Also without the chromium and nickeLthe heat treatment of the alloys can be .conductedat higher temperatures and longer heat treating times, than when these (Cr and Ni) are present, and improved physical properties in the heat treated alloys can .be se-'- cured thereby.

Preferably I also omit'the addition'of alumie num,'vanadium, titanium, columbium, beryllium and alkali metals, all of which are expensive and would be injurious in'my products.

The semi-alloy steel, of the present case con- 40 tains the following:

Percent Carbon 2.25 to 3.25 51110011. 1.75 to 2.25 Manganese s 0.60 to 0.75- Molybdenum 0.35 to 0.60

The balance is madeup essentially of iron; toe gather with suchsmall amounts of impurities as are'usually found present therein:

Thesemi-alloy steel can be prepared for -'ex-- ample, by mixing together pig iron :or cast iron oihigh totalcarbon and-silicon contents,-.With ferromanganese.-and :ferromolybdenum, such. amounts-astofgive the analysis above.

Processing To the solid mixture of'components', a small amount, such as 0.02% to 0.04 %..of calcium boride canrbe added, e. g. before-melting the mixture tdform. the alloy. Or the same amount of the, boride canJoe added to the solid'semi-alloysteeh; which'islto be melted 'byheating inaturrracez- A better plan 'is' 'to' first'm'elvthe semialloyfisteel-iand to 'then-add""the'*said*amount of calcium 'bori'de;.vpreferably atithe:abottomrezoflztherbatchirl sayfwhile :the molten-imetalaisain;a;.1adle 01101 111} cible. This acts as a dGOXidiZGliiblltq dOGSuIlOt leave more than traces of boride in th molten alloy. The treatment; imparts'xveryms'eful properties thereto... When. using. these small amounts oil-the borida, .usuallyl-not. more thamaminute trace. (itany) of; boronwillloefound insthe. steeLl. aftertreatment. and .removalQof. the, slag,

Also at the bottom of the mass of "molten alloyg'r itlisuvery,advisablelto add 0.04%,to 0.06%?013' ferroboronz. Thisrlatter and the calcium'boride also, ifQdesiredyis; preferably first ipla'cedima. closed container, e. g. into a sheetj'iron box (e'.,.g.j.. ftini can), the cover being sold'ered shut. In makinglexperimental batches,I have used empty, tin tobacco cans, of'the pocket "size and also: pound size, eachlattached to the end of a heavy copperwire- When'this box is 'plungedto the bottom of the meltedmetal' alloy irij aladle, the

can melts, the can contents melt and the lower endrof the copper wire melts and these of course dissolve and react withfl-th'e molten. alloy,- to. purify :and improve samel The moltenalloy can be .cast. in semiesteeliand cast or forged into the desired shaped "articles .01.

cast as ingots androlledor otherwise, made. into sheets, rods, rails, etc.. in alloysteelh Heat treatment The shaped articles canthen'be-given aheat'" treatment to improve and temper-"the same:=

In this; the first step is to '-n0rmalize*-' the alloy; and consists in"-heating-same--*to about 45. 1600='F. to about -1700 'F: fora period equal to sevenhours for 'each inchin-thickness of the shaped article. This can be done in a furnace; and-it is not necessary to provide a special atmosphere of inert or reducinggasin-=said'furnace,--

50 prior to this step.

Then'the articlevis allowed to cool (preferably slowly) down to about 1200 F. to 1250 F. Depending on thesizeof the articles andtherrater. ofcooling, the time for this step varies consider-s Then the article is quenched in oil, by immersion, down to a temperature of about 400 F. to about 450 F.

Then the articles are reheated to about 800 F. to 900 F. for a period of about 2 hours for each inch of thickness.

The articles are then quenched, e. g. in water, or a water fo or are cooled by a blast of cold air down to a temperature of about 75 F. to 100 F.

Properties of product The articles, made as above described, from the semi-alloy steel are found to have the following properties:

Tensile strength pounds 70,000 to 80,000 Yield do 40,000 to 50,000 Elongation per cent 3 to 5 Reduction in area do 1.5 to 3 Brinell hardness 550 to 600 I give the following example of the alloy steel."

Composition Per cent Carbon .55 to .75 Silicon .55 to .65 Manganese .75 to 1.25 Molybdenum .60 to .90

Chromium, nickel, aluminum, vanadium, absent. Balance, iron and such impurities as are commonly present in iron.

Preparation and processing The alloy can be prepared by methods analogous to those given for the above semi-alloy steel, or by adding low carbon, low silicon iron to the semi-alloy steel, of the above stated composition.

This alloy steel can be purified and processed similarly to the above, but using about 0.03% to 0.06% of calcium boride and about 0.05% to 0.07% of ferroboron.

The alloy steel after casting etc. as above, preferably is subjected to a heat treatment, as follows:

For normalizing the steel is heated to about 1750 F. to 1850 F. for a period of about 2 to 3 hours for each inch of thicknes of the metal article.

The metal articles are then allowed to cool down to about 1550 F. to 1650 F. The articles are then quenched by dipping in oil, until the temperature of same has fallen to about 450 to 500 F.

Then the articles are reheated to about 900 F. to 1000 F. for about 1.5 hours for each one inch of thickness of said articles. Then the articles are quenched in water or fog of water particles, or cooled in air down to about 75 F. to 100 F.

It will be noted that in the processing of the alloy steel, somewhat more of the chemicals are used, and in the heat treatment of the alloy steel, the temperatures are somewhat higher, both as compared with the treatment of the semi-alloy steel.

The treated alloy steel is found to have the following physical properties:

Tensile strength (square inch) pounds 190,000 to 230,000

Yield do 170,000 to 200,000 Elongation per cent 7.5 to Reduction in area do 8to 9 Brinell hardness 425 to 525 Thus it is seen that the alloy steel," after the heat treatment, is much strogner than the treated semi-alloy steel.

Both alloys, treated as above, are highly abrasive resistant, highly shock resistant, and they are suitable for making high speed gears, grinding media, armour plates, grinding mills, drilling bits, and various other articles.

It will be noticed that the physical properties for semi-alloy steel are limited in ductility, that is the semi-alloy steel has a very high abrasion resistance which is measured by its hardness. The other physicals are much lower than those of the alloy steel. Its use is therefore indicated when high abrasion resistance is necessary and some shock resistance can be given up for the extra abrasion resistance obtained. Where some abrasion resistance can be sacrificed for additional shock resistance, the use of alloy steel is indicated as noted from the high physicals and the lower hardness obtained. The chemical constituents, the processing and the heat treatment in combination, are varied to the extent as given in order to attain the physical properties noted.

The indicated uses for semi-alloy steel are grinding media for use in the mining fields, paint production, cement, lime and asbestos field, inner shell wearing plates of grinding mills, in the grinding of talc and all hard ceramic materials. The indicated uses for the alloy steel are transmission chain, caterpillar treads, gears, especially high speed, pins, bushings, grinding rolls, grinding rings, tires for trunnions, pulleys. In enumerating these uses, I do not want to limit either the use of semi-alloy steel or alloy steel but I wish to use them for all applications where a high abrasion resistant steel is required in semialloy steel or a high shock resistant steel is required in alloy steel.

I claim:

1. A process of heat treating an iron alloy having the approximate composition in the range of Per cent Carbon .5 to 3.25 Silicon .55 to 2.25 Manganese .60 to 1.25 Molybdenum .35 to .9

the balance consisting essentially of iron and usual impurities, and formed by adding a deoxidizer and introducing solid ferroboron into the bottom of a melt thereof in quantity of 0.04 to 0.07%, to convert said iron alloy to a product of high shock and abrasion resistant character, comprising heating the iron alloy to a normalizing temperature in the range of about 1600 to 1850 F., cooling the normalized iron alloy to an intermediate temperature in the range of about 1200 to 1650 F., quenching in oil to the range of 400 to 550 F., reheating the iron alloy to an inter-mediate temperature in the range of about 800 to 1000" F. and finally quenching to a temperature below about F.

2. A process of heat treating an iron alloy having the approximate composition in the range of Per cent Carbon .5 to 3.25 Silicon .55 to 2.25 Manganese .60 to 1.25 Molybdenum .35 to .9

the balance consisting essentially of iron and. usual impurities, and formed by adding a deoxidizer comprising calcium boride in proportion of 0.02% to 0.06% to a melt thereof and introe cseg rass ducing -into-the-bottom of--- the :melt lferro-eboronw 1'. in proportion of .04 to 107% to convert said ironi; alloy to a product. of high: shock and abra-sionresistant character; comprisingheating the iron alloy to a normalizing temperature in the range 2- of about 1600 to 1850 F., cooling the normalized iron alloy--= to an intermediate temperature in the range of about 1200 to 1650 F., quenching in oil to the range of-about 400'130"550 "Fi re-heating the. steel .ito; an intermediate ;temperatur.e ;in;the

range of about 800 to 1000 F. andfinallyquenche ing to a temperature below. about 100?. F.

3. A process of heat treating an iron alloy having theapproximate composition in the range; of:

I Percent- Carbon 0.55; to 0.75 Silicon g 0.55-to 0.65: Manganese um w 0.75;.to 1.25:- Molybdenum r 0.6 to. 0.91

usual impurities and formed by-adding to the melt thereof about 0.03 to .06 :percent of calcium boride and-by introducingferro-boron into the bottom of a melt thereof in quantity of about .05 to .07 percent to convert said steel to a product of high shock and abrasion resistant character, comprising heating the iron alloy to a normalizing temperature in the range of about 1750 to 1850 F., cooling the normalized iron alloy to an intermediate temperature in the range of about 1550 to 1650 F., quenching in oil to lower the temperature to the range of about 450 to 550 F., re-heating the iron alloy to an intermediate temperature of about 900 to 1000 F. and finally quenching to a temperature below about 100 F. 4. A process of treating an iron alloy having the approximate composition in the range of:

Percent Carbon 2.75 to 3.25 Silicon 1.75 to 2.25 Manganese .60 to .75 Molybdenum .35 to .6

the balance consisting essentially of iron and usual impurities, and formed by introducing a solid non-oxidized compound of boron into the bottom of a melt thereof in quantity of .02 to .1%, to convert said iron alloy to a product of high shock and abrasion resistant character, comprising heating the iron alloy to a normalizing temperature in the range of about 1600 F. to 1700 F. for a period equivalent to about seven hours for each inch of iron alloy thickness, allowing the iron alloy to cool to a temperature in the range of about 1200 F. to 1250 F., quenching in oil to a temperature in the range of about 400 to 450 F., reheating the iron alloy to an intermediate temperature in the range of about 800 F. to 900 F. for a period of about two hours for each inch of iron alloy thickness and finally quenching to a temperature not substantially exceeding 100 F.

5. A process of heat treating an iron alloy having the approximate composition in the range of:

Percent Carbon .55 to .75 Silicon .55 to .65 Manganese .75 to 1.25 Molybdenum .60 to .9

the balance consisting essentially of iron and usual impurities, and formed by introducing a solid non-oxidized compound of boron into the bottom of a melt thereof in quantity of .03 to .13%, to convert such iron alloy to a product of night-x shocks; and.:.:' abrasions: resistantigcharactenzz. heating the-:irontwalloy toe:amormalizingfimperw ature in::th'e;range :ofraboutx1750f; to..-18.50.3.. fo'r 'a period of: labout two.tothree hoursafor each:

i inch of thickness of the iron alloy, cooling-l the;

sameto-about 15509 to::about:.1650?;F.; .quench. ing 'inzoil' toxlowerzthe:temperaturextozzthe;ranger. of .about,.450 F. to 550 F., reheating to the range of 90.0". F. to 1000 F. for a period of aboutone.

.tatwo-hours for each inch of thicknessv ofjtha.

iron allots-rand then quenching to a temperature... below about F.

6. An iron alloy product of high abrasion and" shock resistant character having -theapproximate composition in --the--.-range--of-i Percent- Carbon .5 to-3.25::1=. Silicon .55ito 2;2'5 Manganese; .60 to -:1.25:Z

Molybdenum: v.35. tor.

the. balance consisting... essentially or iron, and; usual .impurities,-, saidiron, alloybeing. fo'rmedfbya introducing a. .solid, non-.oxidized compound "of. i boron into the bottom of the melt in quantity of .02 to 13%, heating the cold solidified melt to a normalizing temperature in the range of about 1600 to 1850 F., cooling the normalized iron alloy to an intermediate temperature within the range of about 1200 to 1650 F., quenching in oil to lower the temperature to the range of about 400 to 550 F., re-heating the iron alloy to an intermediate temperature in the range of about 800 to 1000 F. and finally quenching to below about 100 F.

7. An iron alloy product of high abrasion and shock resistant character having the approximate composition in the range of:

Percent Carbon 2.25 to 3.25 Silicon 1.75 to 2.25 Manganese 0.60 to 0.75 Molybdenum 0.35 to 0.60

the balance consisting essentially of iron and usual impurities, said iron alloy being formed by introducing a solid non-oxidized compound of boron into the bottom of the melt in quantity of .02 to .1%, heating the cold solidified melt to a normalizing temperature in the range of about 1600 to 1700 F., cooling the normalized iron alloy to an intermediate temperature in the range of about 1200 to 1250 F., quenching in oil to a temperature in the range of about 400 to 450 F., re-heating the iron alloy to an intermediate temperature in the range of about 800 to 900 F., and finally quenching to below about 100 F.

8. An iron alloy product of high abrasion and shock resistant character having the approximate composition in the range of:

Percent Carbon 0.55 to 0.75 Silicon 0.55 to 0.65 Manganese 0.75 to 1.25 Molybdenum 0.6 to 0.9

the balance consisting essentially of iron and usual impurities, said iron alloy being formed by introducing a solid non-oxidized compound of boron into the bottom of the melt in quantity of .03 to .13%, heating the cold solidified melt to a normalizing temperature in the range of about 1750 to 1850 F., cooling the normalized iron alloy to an intermediate temperature in the range of about 1550 to 1650 F., quenching in oil to lower the temperature to the range of about 450 to 550 F., re-heating the iron alloy to an intermediate temperature in the range of about 900 to 1000 F., and finally quenching to below about 100 F.

9. A process of heat treating an iron alloy having the approximate composition in the range of:

Percent Carbon .5 to 3.25 Silicon .55 to 2.25 Manganese .60 to 1.25 Molybdenum .35 to .9

the balance consisting essentially of iron and usual impurities, formed by introducing a solid nonoxidized compound of boron into the bottom of a melt thereof in proportion of .02 to 13%. comprising heating the iron alloy to a normalizing temperature in the range of about 1600 to 1850 F. for a period of two to about seven hours for each inch of thickness of the iron alloy, cooling the same from a higher normalizing temperature to the range of about 1200 to 1650 F., quenching in oil to lower the temperature to the 8 range of about 400-500" F., reheating to the range of 800-1000 F. for a period of about 1-2 hours for each inch of thickness of the iron alloy, and then quenching to a temperature below about 100 F.

DAVID J. UHLE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,401,925 Sargent Dec. 27, 1921 1,519,388 Walter Dec. 16, 1924 1,718,685 De Vries June 25, 1929 1,785,060 White Dec. 16, 1930 2,004,774 Valentine June 11, 1935 2,014,440 Lee Sept. 17, 1935 2,209,248 Krause et a1 July 23, 1940 2,283,299 Tisdale May 19, 1942 2,509,281 'Iisdale May 30, 1950 2,513,395 Bargett July 4, 1950 

1. A PROCESS OF HEAT TREATING AN IRON ALLOY HAVING THE APPROXIMATE COMPOSITION IN THE RANGE OF: 